Pteronarcys stoneflies, called Giant Stoneflies by most eastern fly fishers and Salmonflies by their western counterparts have been one of the few constants no matter where I've lived for the past 20 years. I often found them at the end of May near my home along the Upper Delaware in New York. And it was the same when we lived across the street from Central Pennsylvania's Penns Creek. Now that I live in Southwest Montana, I encounter them in late June or early July, just as runoff is receding, crawling along the mighty Yellowstone River's rocks and streamside vegetation. My good friend and hatch matching legend, Charlie Meck, once told me that the heaviest Salmonfly hatch he witnessed was in the Yellowstone just outside of Gardiner, MT.
Charlie also gave me my first glimpse of a western Salmonfly. He brought a live one back from the Metolious River in a styrofoam coffee cup and gave it to me as a gift. I photographed it on my kitchen table in Pennsylvania. I don't believe that airline security would approve of sneaking live critters on board today. But it happened.
Pteronarcys stoneflies have a 3 year life cycle, so their nymphs are often available to trout. The great Rubberlegs nymph fly pattern is an excellent imitation, and it fools trout east or west. I fish it often in Montana from ice out until summer low flows instigate dry fly action and reduces the pattern's effectiveness.
We're about to have a warm week here in Montana with highs from the mid forties to low fifties, and I plan to fish the Yellowstone before too much low elevation snow melts, turning the river off-color. We still have feet of snow on the ground so a lot of runoff is about to begin. I better get fishing.
